The PIN code of the set top box (STB) is used by the user to access some critical configurations. However, the user may forget or lose the PIN code sometimes. At present, a hard code number combination is used as a solution. Generally, the hard code number is a kind of universal code to access the critical configurations of the STB. When the PIN code is lost, the operator will send an engineer to restore the default configuration, which is also called factory configuration, by using the hard code number combination in the user's home, and then reset the PIN code for the user.
However, the solution is not convenient to some extent, firstly, the hard code number combination is hard coded, namely, all STBs' hard code number combinations are the same; secondly, the operator needs to send an engineer to user's home, and so it will cause some travel costs.